Connection control method

Abstract

A connection control method in a substrate processing apparatus is provided. The substrate processing apparatus comprises: a depressurized processing room; a susceptor that is provided in the processing room and configured to mount a wafer thereon; a HF high frequency power supply configured to apply a high frequency voltage for plasma generation to the susceptor; a LF high frequency power supply configured to apply a high frequency voltage for a bias voltage generation to the susceptor; and a DC voltage applying unit configured to apply a DC voltage of a rectangle-shaped wave to the susceptor, capable of improving a processing controllability in an etching process. The connection control method comprises controlling connection or disconnection between the susceptor and the LF high frequency power supply and connection or disconnection between the susceptor and the DC voltage applying unit when plasma is generated in the processing room.

We claim: 
     
       1. A connection control method in a substrate processing apparatus comprising: a depressurized processing room; a mounting table that is provided in the processing room and configured to mount a substrate thereon; a first high frequency power supply configured to apply a high frequency voltage for plasma generation; a second high frequency power supply configured to apply a high frequency voltage for bias voltage generation to the mounting table; and a DC voltage applying unit configured to apply a DC voltage of a rectangle-shaped wave to the mounting table, the connection control method comprising:
 controlling connection or disconnection, by a first switch that is not connected to a ground but connected to the second high frequency power supply, between the mounting table and the second high frequency power supply and connection or disconnection, by a second switch that applies the DC voltage to the mounting table so as to change an energy distribution of ions attracted to the mounting table, between the mounting table and the DC voltage applying unit when plasma is generated in the processing room. 
 
     
     
       2. The connection control method of  claim 1 ,
 wherein, in the step of controlling, the connection or the disconnection between the mounting table and the second high frequency power supply and the connection or the disconnection between the mounting table and the DC voltage applying unit are controlled individually. 
 
     
     
       3. The connection control method of  claim 2 ,
 wherein, in the step of controlling, the second high frequency power supply is disconnected from the mounting table if the DC voltage applying unit is connected to the mounting table, and the DC voltage applying unit is disconnected from the mounting table if the second high frequency power supply is connected to the mounting table.